International Research Journal of Engineering and Technology (IRJET) Volume: 03 Issue: 06 | June-2016
www.irjet.net
e-ISSN: 2395 -0056 p-ISSN: 2395-0072
“Design & Analysis of Hydraulic Scissor Lift” M. Kiran Kumar1, J. Chandrasheker2, Mahipal Manda3 , D.Vijay Kumar4 1,2,3,4Assistant Professor, Department of Mechanical Engineering Vaageswari college of Engineering,
Karimanagar, Telangana, India ------------------------------------------------------------------------***--------------------------------------------------------------
Abstract -This paper is mainly focused on force
acting on the hydraulic scissor lift when it is extended and contracted. Generally, a hydraulic scissor lift is used for lifting and holding heavy weight components. Material selection plays a key role in designing a machine and also influence on several factor such as durability, reliability, strength, resistance which finally leads to increase the life of scissor lift.
The design is performed by considering hydraulic scissor lift as a portable, compact and much suitable for medium type of load application. Drafting & drawing of hydraulic system scissor lift is done using solid works with suitable modeling and imported to Ansys work bench for meshing and analysis. Hence, the analysis of the scissor lift includes Total deformation load, Equivalent stress, was done in Ansys and all responsible parameters were analyzed in order to check the compatibility of the design value. The computational values of two different materials such as aluminum and mild steel are compared for best results Key Words: Hydraulic scissor lift, Solid works, Ansys work bench, Total deformation load, Equivalent stress.
1. INTRODUCTON Any machine part cannot be moved to a desired position with application of less amount of external force. For placing a component in required location, the motion of component follows commonly horizontal or vertical direction. Many machines such as aerial lift, boom lifts, scissor lift, man lift, tele handler, towable lift are used to move machinery and manpower in different directions based on the requirement. A scissor lift is a portable, easily extended and compressed, safe operating machine used for
transportation of medium sized components to its expected position. A scissor lift is machine which moves in vertical direction using criss-cross 'X' pattern scissor arms. The required elevation of the lift is achieved based on the number of criss-cross 'X' pattern scissor arms attached. The scissor lift mechanism is based on linked arms in a criss-cross 'X' pattern which can be folded and extended in exact direction similar to a pantograph. The upward motion is achieved by the application of pressure to the outside of the lowest set of supports, elongating the crossing pattern, and propelling the work platform vertically upwards. The platform may also have an extending 'bridge' to allow closer access to the work area. 1.1 Types of Scissor lift The scissor lifts can be classified as follows:
Hydraulic lifts Pneumatic lifts Mechanical lifts
Hydraulic scissor lifts are very powerful tool for applying a ton of force on the platform plate of component which is equally distributed on scissor arms.
2. METHODOLOGY Deflection in scissors lifts can be defined as the change in elevation of all parts to the original size of entire assembly i.e from the floor to the top of platform deck, whenever loads are applied to or removed from the lift. Each component within the scissors lift has the potential to store or release
© 2016, IRJET
ISO 9001:2008 Certified Journal
Page 1647
International Research Journal of Engineering and Technology (IRJET) Volume: 03 Issue: 06 | June-2016
e-ISSN: 2395 -0056
www.irjet.net
energy when loaded and unloaded. Deflection takes place in all parts of scissor lift i.e Scissors Legs, Platform
p-ISSN: 2395-0072
Table-3: Mechanical properties of Al (6061) Sl.no
Mechanical composition
Structure, Base Frame, Pinned Joints. To reduce stresses
1
Ultimate tensile stress
310 Mpa
and deflection in scissor lift the load should transfer
2
Modulus of elasticity
68.9 Gpa
3
Ultimate strength
607 Mpa
equally between the two scissors arm pair. Base frames
4
Poisson ratio
should be attached to the surface on which they are
5
Fatigue strength
6
Machinability
7
Shear strength
207 Mpa
8
Tensile yield strength
276 Mpa
mounted.
2.1 Single Acting Hydraulic Cylinder
0.33 96.5 Mpa 50 %
Single acting cylinders use hydraulic oil for a power stroke in one direction only. Some external force acting
Table 4: chemical composition of (AL) 6061
on the piston rod causes its return. Most applications Silicon
require a single acting cylinder with the spring pushing
0.40-0.8
Ferrous 0.7
Copper
Manganese
0.15-0.40
0.8-1.2
Zinc
Titanium
0.25
0.15
the piston and rod to the in stroked position.
3. FINITE ELEMENT METHOD: By using solid work (2010), modeling of scissor lift was done and then it was imported to Ansys14.0 for the Fig -1: Hydraulic cylinder
analysis of scissor lift. The goal of meshing in ANSYS Workbench is to provide robust, easy to use meshing
2.2 Material Selection Material selection plays a very important role in machine design. Two metals are considered for the analysis of Table 1: Chemical composition of mild steel Carbon
Silicon
Manganese
Sulphur
0.40%
0.70-0.90%
0.040%
this hydraulic scissor lift automation meshing is applied and complete analysis of scissor lift was done.
scissor lift is mild steel & aluminum.
0.16-0.18%
tools that will simplify the mesh generation process. In
Phosphorous 0.040%
4. MODELING All the parts of scissor lift which must be designed and assemble are given below:
Table -2: Mechanical composition of mild steel
4.1 Scissor lift platform: It is required to design a platform which should serve under heavy load
Sl.no
Mechanical composition of mild steel (ms) BS970
1
Max stress
400-560 n/mm
2
Yield stress
300-440 n/mm
3
0.2% proof stress
280-420 n/mm
4
Elongation
10-14 % min
application and withstand high stresses.
Fig 2: Scissor lift platform
© 2016, IRJET
ISO 9001:2008 Certified Journal
Page 1648
International Research Journal of Engineering and Technology (IRJET) Volume: 03 Issue: 06 | June-2016
e-ISSN: 2395 -0056
www.irjet.net
p-ISSN: 2395-0072
4.2 Scissor arm: In modeling of scissor lifts scissor arms
The maximum extension length and closing length of
plays a key role it bears the loads and lift platform.
scissor lift can be observed to the value of raise up to 1828mm when it is opened. This scissor lift can be close up to 150mm when it is closed.
Fig 3: scissor arm
4.3 Coupler: In modeling scissor lift, couplers are fixed
Fig 7: Open scissor lift
joints with support the hydraulic cylinder to lift the plate.
The rollers roll back towards the platform hinges and create an increasingly unsupported, overhung portion of the platform assembly.
Fig 4: coupler
4.4 Cylinder: In modeling scissor lift cylinder are placed to lift the heavy loads on the platform.
Fig 8: Closed scissor lift The technical specifications of a Hydraulic Scissor lift is given below in a tubular representation Table 5: Technical specification
Fig 5: cylinder of scissor lift All the parts shown above are assembled to form a
Sl.no
Type
Hydraulic-Scissor Type
1
Capacity
750 Kgs
2
length
6 foots = 1828 mm
complete structure of hydraulic scissor lift which is
3
Lifting height
3 foots = 914 mm
represented in figure below.
4
Closing height
150 mm
4.5 Wire Frame of Scissor Lifts The frame is a carriage which serves as a support for the occupant and the other components to be added on. The frame is made of aluminum or stainless steel. Fig 6: Various individual parts of scissor lift © 2016, IRJET
ISO 9001:2008 Certified Journal
Page 1649
International Research Journal of Engineering and Technology (IRJET) Volume: 03 Issue: 06 | June-2016
e-ISSN: 2395 -0056
www.irjet.net
p-ISSN: 2395-0072
Fig 9: Wire frame of scissor lift
5. ANALYSIS
Fig 11: Total deformation load
The mesh influences the accuracy, convergence and speed of the solution. Below figure shows automatic type of triangular meshing.
5.2 For Aluminum: The maximum deformation for aluminum 147.55 mm and the minimum deformation is 1.75mm. The maximum equivalent stress value for (Al) is 178.41 and the minimum equivalent stress value is 6.307MPa.
Fig 10: Triangular meshing Table 6: Nodes and elements Bodies
Active Bodies
44
31
Nodes 86745
Elements 35478
Fig 12: Equivalent stress 5.1 For mild steel:
5.3 Joint Velocity with Load:
Total deformation of entire scissor lift is evaluated by applying a load of 300 kg. The maximum deformation for
For analysis of joint velocity load with 10mm/s are applied on scissor lift.
mild steel is resulted as 77.851mm and the minimum deformation is 6.143mm. The maximum equivalent stress for mild steel is given as 150.67MPa and the minimum stress value is 1.6083MPa.
Fig 13: Joint velocity with load
© 2016, IRJET
ISO 9001:2008 Certified Journal
Page 1650
International Research Journal of Engineering and Technology (IRJET) Volume: 03 Issue: 06 | June-2016
www.irjet.net
e-ISSN: 2395 -0056 p-ISSN: 2395-0072
Total deformation load of entire scissor lift is represents in below figure with max & min points.
Graph of comparing both the stress analysis MS & Al
Fig 14: Total deformation graph with load Graph of total deformation with load(ms)
RESULTS In this project the analysis was done on two metals such as mild steel and aluminum alloy using Ansys 14.0 version. The results are shown in the table below
Graph of total deformation with load(Al)
© 2016, IRJET
ISO 9001:2008 Certified Journal
Page 1651
International Research Journal of Engineering and Technology (IRJET) Volume: 03 Issue: 06 | June-2016
www.irjet.net
e-ISSN: 2395 -0056 p-ISSN: 2395-0072
Table 7: Deformation and Equivalent stresses Sl.n
Metal
Total
o
Equivalent
deformation
stress
with load
(vonmisses
Load
Joint velocity
stress)
1
Max
Min
Max
Min
Mild
77.85m
6.1m
150.6
1.60
100
steel
m
m
mpa
mpa
N
10 mm/s
(MS) 2
Alumin
147.5m
1.7
178.4
6.30
100
um
m
mm
mpa
mpa
N
10 mm/s
alloy (AL)
6. CONCLUSION Portable work platform hydraulic scissor lift is designed for high load resistance. The hydraulic scissor lift is simple
in
use
and
does
not
required
routine
maintenance. Both the mild steel and aluminum alloys are good at their different aspects. Mild steel has greater durability strength and it is also cheap and easily available. As these properties plays an important role in designing scissor lift. So in designing scissor lift mild steel has greater importance.
[7] An investigation on the dynamic stability of scissor liftRen G. Dong, Christopher S. Pan, Jared J. Hartsell, Daniel E. Welcome, [8] Scissor lift apparatus for work platforms and the likeRichard E.Cullity. [9] IS800-2007 General constants in steel. 13. Properties of rectangular hollow section. - TATA structural steel IS4923. [10] Specifications of tubular members- IS1161. [11] Design of transmission elements-. T.J Prabu. [12] Design of round tubular structure Design of steel structures- B.C.Punmia. [13] Multibody Dynamics: Rigid and Flexible Methods- By Steve Pilz. [14]Design and analysis of an aerial scissor lift-abhinay. [15]Design, Analysis and Development of Multiutility home equipmentusing Scissor Lift-Divyesh Prafulla Ubale. [16]Design, Manufacturing & Analysis of Hydraulic Scissor Lift- Gaffar G Momin. [17]Design and kinematic analysis of gear powered scissor lift- a.roys jeyange,m.babu. [18]Intelligent lifting mechanism for pepper harvester-firas b. ismail, vinesh thiruchelvam, wilson you wei lim [19] Understanding Scissors Lift Deflection-Michael Adel, PE [20] Desing and calculation of the scissores-type elevating- platform-beqir hamidi
REFERENCES [1] Design and construction of hydraulic scissors liftOkolieizunnajude. [2] Design and analysis of an aerial scissor lift-Jaydeep m. Bhatt ,Milan j. Pandya. [3] Designed a belt-driven transportation system-Todd J. Bacon [4] Scissors lift platform with electronic control-Arturo Valencia Ochoa Jaime Antonio Uribe. [5] Scissor lift mechanism employing telescopable electro-mechanical based lift actuation arrangementEnoch L. Newlin. [6] The aerial platform falls across all industries classifications- Mahmood Ronaghi, John Z. Wu, Christopher. © 2016, IRJET
ISO 9001:2008 Certified Journal
Page 1652
International Research Journal of Engineering and Technology (IRJET) Volume: 03 Issue: 06 | June-2016
www.irjet.net
e-ISSN: 2395 -0056 p-ISSN: 2395-0072
BIOGRAPHIES
Kiran Kumar Madisetty obtained his M.E (CAD/CAM) from CBIT, Osmania University. He has teaching experience of 6 years. He is currently working as Assistant professor in the Mechanical Engineering department of Vaageswari College of engineering, JNTU. Has a vast experience of guiding projects for B. Tech and M. Tech. students. Email:
[email protected]
D.Vijay kumar obtained his M.Sc (Structural Mechanics) from BTH Sweden. He has teaching experience of 8 years. He is currently working as Assistant professor in the Mechanical Engineering department of Vaageswari College of engineering, JNTU. Email:
[email protected]
Mahipal Manda obtained his M.Tech (CAD/CAM) from SVNIT, Surat. He has teaching experience of 6 years. He is currently working as Assistant professor in the Mechanical Engineering department of Vaageswari College of engineering, JNTU. Has a vast experience of guiding projects for B. Tech and M. Tech. students. Email:
[email protected]
J. Chandrasheker obtained his M.Tech (Advanced Manufacturing Systems) from VNR Vignana Jyothi Institute of Engg & Tech. JNTU - Hyderabad. He has teaching experience of 8 years. He is currently working as Assistant professor in the Mechanical Engineering department of Vaageswari College of engineering, JNTU. Has a vast experience of guiding projects for B. Tech and M. Tech. students. Email:
[email protected]
© 2016, IRJET
ISO 9001:2008 Certified Journal
Page 1653